This study reexamines the monetary functions of gold and silver during the Northern and Southern Song dynasties, focusing particularly on their roles within the public fiscal sphere―an aspect largely understudied in previous scholarship. Although gold and silver did not replace copper coins, iron coins, or Southern Song paper money as universally circulating media, they served as essential high-value instruments for state-level transactions that required rapid and concentrated disbursement, such as monopoly exchange, tax payments, military provisioning, and relief expenditures. From the early Northern Song onward, gold and silver were institutionally incorporated into the exchange and taxation of government monopolies―namely alum, tea, and salt―alongside copper cash and textiles, with flexible mixed-payment ratios (40:60, 50:50, 60:40) adjusted by time and region. These precious metals were centrally accumulated in the Inner Treasury (Neicangku) and their usage strictly regulated through the fengzhuang system, which designated specific purposes and prevented diversion. Owing to their high value relative to weight and volume, gold and especially silver significantly reduced transportation costs and risks, enabling efficient procurement of grain, fodder, and relief materials. The state employed administrative mechanisms such as pinggu (market-based valuation) and the Ever-Normal Granary system to stabilize conversion between precious metals and physical goods, mitigating market volatility. However, uneven regional supply―stemming from mining scarcity, compulsory state purchases, and transport levies―raised acquisition costs and created local disparities. In response, the state adjusted payment ratios and permitted alternative contributions. Ultimately, gold and silver in Song China functioned not as mere stores of wealth, but as strategic fiscal assets embedded in a state-designed cycle of absorption, concentration, conversion, and disbursement, forming the apex layer of the multi-tiered monetary system.